Spondylodesis implants of this kind are known in various embodiments for instance from DE 31 32 520 C2 or DE 33 06 657 C2 and differ from each other by the type and manner of the relative guiding and distance adjustment of the connection pieces, as well as by design of the receiving pieces for the resetting screws provided at the connection piece. It is common to all these known embodiments that the force-locking between the connection pieces and the resetting screws is basically achieved through the screw heads, which presumes that the resetting screws must have a precisely defined length for each particular case. This insures that within the limits of the acceptable maximal, respectively the required minimal depth of engagement the head of the resetting screw is each time in the correct position for being received in the connection pieces.
Therefore the resetting screws need not only be stored in a variety of lengths, but also must be selected in the precisely correct length prior to being screwed in, which is cumbersome and can create complications. Although it is already known to avoid these drawbacks by using headless resetting screws, so-called SCHANZ screws, which adjacent to the threaded shaft portion have a longer, smooth shaft segment to be shortened to the respective required length after implant, problems arise in these cases when the resetting screws have to be connected rigidly enough for the fixation with the connection pieces, especially then when the inclined position of the resetting screws has to be taken into consideration with respect to the mutual adjustment direction of the connection pieces.